1. Field of the Invention
The present invention relates generally to fuel injection systems for automobiles, and more particularly to an automobile fuel injection system designed for increasing the overall fuel efficiency of automobiles.
2. Description of the Prior Art
Fuel injection systems have replaced carburetors as the predominant type of fuel system used in automobiles. In response to increasingly stricter automobile emissions requirements, as well as to keep up with evolving fuel efficiency laws and regulations, electronic fuel injection systems have undergone significant changes since their inception. Many of the changes in the design and configuration have related to the air-to-fuel ratio. Particularly, in any electronic fuel injection system, careful control of the air-to-fuel ratio is required to maximize power and optimize fuel efficiency.
In typical multi-port fuel injection systems, the amount of fuel supplied to the engine is determined by the amount of time the nozzles of the fuel injectors remain open, also referred to as the xe2x80x9cpulse width.xe2x80x9d A lean air-to-fuel ratio is obtained by minimizing the pulse width. Likewise, a greater pulse width results in a richer air-to-fuel mixture. In conventional automobile engines, an engine control unit calculates an appropriate pulse width based upon a variety of carefully monitored engine performance and operating conditions such as engine temperature, the amount of air entering the throttle valve, the amount of oxygen in the exhaust, fuel pressure, throttle position, intake manifold air pressure, engine speed, and the like. The engine control unit utilizes this information to calculate a specific pulse width for the given operating conditions in order to maximize power and fuel efficiency.
It is known that for internal combustion engines to run efficiently, the air-to-fuel ratio must be within a range of 8-to-1 and 18.5-to-1 at sea level. The temperature of the cylinder and injector nozzles decreases as the richness in the fuel mixture increases. Conversely, as the fuel mixture becomes leaner, the temperature of the cylinders and injector nozzles increases.
The engine temperature is an important variable in maximizing engine power and fuel economy. Specifically, the temperature in the head of each of the cylinder injector nozzles of an engine has a substantial and direct effect upon the air-to-fuel ratio necessary to maximize power and fuel economy. In existing automotive fuel injection systems, an approximation of the temperature in the head of each of the injector nozzles is obtained by measuring the temperature in the engine chamber. Consequently, electronic fuel injection systems of existing automotive internal combustion engines do not directly measure the specific temperature in the head of each of the injector nozzles within the cylinder of the engine.
Coolant circulation control is limited in conventional liquid-cooled engines by a thermostat having an open and a closed configuration. The function of the thermostat is simply to block the flow of coolant until the engine has sufficiently warmed up.
The thermostat opens to permit engine coolant to flow when the opening temperature reaches a predetermined preset value. In many automobile engines, this value is typically around 199 degrees Fahrenheit. Once the thermostat is open, the coolant flowing through the engine heat intercooler reduces the engine temperature. As the temperature approaches a lower preset value, typically around 175 degrees Fahrenheit, the thermostat closes to stop the flow of coolant circulation.
By allowing an engine to warm up as quickly as possible, the cooling system helps reduce engine wear, deposits and emissions. Once the engine reaches the preset target temperature, however, the thermostats of existing cooling systems open completely to permit coolant flow throughout the engine and throughout the heat exchanger, e.g., the radiator. Once the engine is sufficiently warmed, the thermostats of existing cooling systems remain open as long as the vehicle is running and the engine maintains a minimum temperature. As such, the open/shut configurations of existing cooling systems are not oriented for use in carefully maintaining and adjusting engine temperature so as to maximize power and fuel economy.
Accordingly, there is an established need for a smart fuel injection system overcoming the aforementioned drawbacks and limitations of the prior art. In particular, it would be desirable to provide a smart fuel injection system wherein the engine coolant can be carefully regulated by a coolant valve and, thereby, play an integral part in adjusting and maintaining engine temperature to maximize power and fuel economy. Additionally, a smart fuel injection system is needed that directly measures the temperature in the head of each of the injector nozzles within the cylinder of an engine and utilizes this reading, along with other engine performance and operating condition information, to carefully adjust the air-to-fuel ratio to maximize power and economize fuel.
The present invention is directed to a smart fuel injection system for automobiles wherein engine coolant, temperature measurements from each cylinder injector nozzle head of an engine, and a variety of other known engine performance and operating condition data are utilized to carefully adjust and maintain the air-to-fuel ratio of the engine so as to maximize power and fuel efficiency.
An object of the present invention is to provide a smart fuel injection system configured to substantially reduce the fuel consumption of an automobile engine.
Another object of the present invention is to provide a smart fuel injection system that directly measures the temperature in each cylinder injector nozzle head of an engine and, subsequently, utilizes this reading, along with other engine performance and operating condition information, to carefully adjust the air-to-fuel ratio to maximize power and fuel economy in an automobile engine.
It is another object of the present invention to provide a smart fuel injection system wherein the engine coolant plays an integral part in adjusting and maintaining engine temperature so as to maximize power and fuel economy in an automobile engine.
It is another object of the present invention to provide a smart fuel injection system wherein the quantity of engine coolant passing to the engine can be carefully controlled with substantial precision during operation of the engine.
It is another object of the present invention to provide a smart fuel injection system operating to minimize, and preferably eliminate, the well-established negative thermal inertia effects in existing automotive system engine blocks.
It is another object of the present invention to provide a smart fuel injection system that can be readily incorporated into an automobile engine design and manufacturing process with minimal additional cost.
It is another object of the present invention to provide a smart fuel injection system capable of substantially reducing the fuel consumption of an automobile engine at a wide range of operating altitudes.
It is another object of the present invention to provide a smart fuel injection system capable of substantially reducing the fuel consumption of an automobile under a wide variety of operating and environmental conditions, such as automobile speed and acceleration, operating altitudes, road gradients, traffic conditions, and the like.
These and other objects, features, and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow.
In accordance with a first aspect of the invention, a smart fuel injection system for an automobile is provided for use with a multi-port engine wherein the flow rate of engine coolant, temperature measurements within the heads of the cylinder injector nozzles, and other engine performance and operation condition information is utilized to precisely adjust and maintain the air-to-fuel ratio of the engine and to maximize fuel efficiency.
The smart fuel injection system of the present invention includes a multi-cylinder engine having at least one fuel injector, an engine control unit, a plurality of sensors to measure a variety operating conditions, and coolant control means to continuously regulate the volume of engine coolant flowing to the engine.